/*设置html字体大小，作为 rem 初始参数，用于适合各种类型的手机浏览器，必须放在页头中先执行此方法，否则页面载入时会有突然变大变小的停顿*/
(function(){
    var Dpr = 1, uAgent = window.navigator.userAgent;
    var isIOS = uAgent.match(/iphone/i);

    var wWidth = (screen.width > 0) ? (window.innerWidth >= screen.width || window.innerWidth == 0) ? screen.width : window.innerWidth : window.innerWidth, wDpr, wFsize;
    var wHeight = (screen.height > 0) ? (window.innerHeight >= screen.height || window.innerHeight == 0) ? screen.height : window.innerHeight : window.innerHeight;
    if (window.devicePixelRatio) {
        wDpr = window.devicePixelRatio;
    } else {
        wDpr = isIOS ? wWidth > 818 ? 3 : wWidth > 480 ? 2 : 1 : 1;
    }
    if(isIOS) {
        wWidth = screen.width;
        wHeight = screen.height;
    }
    if(wWidth > wHeight){
        wWidth = wHeight;
    }
    wFsize = wWidth > 1080 ? 144 : wWidth / 7.5;
    wFsize = wFsize > 32 ? wFsize : 32;
    window.screenWidth_ = wWidth;
    var html=document.getElementsByTagName('html')[0];
    html.dataset.dpr = wDpr;
    html.style.fontSize = wFsize + 'px';

})();